Question

when we drink a soft drink with the help of a straw what was the liquid to rise up in the straw

Answer 1

good evening ,

this is because by sucking we reduce the pressure at the top . The cold drink at the bottom is at higher pressure, so the cold drink flows up the straw into our mouth.

hope# helps#

Answer 2

With the straw just sitting in the soft drink , the pressure on the surface of the drink is the same all over, including on the little bit of surface inside the straw.
When you suck the air out of the straw, you decrease the pressure inside the straw, allowing the higher pressure on the rest of the surface to push the drink up the straw and into your mouth.
Because it is really the atmosphere that is doing the pushing, the atmospheric pressure limits how high water will go up a straw. At sea level, the air pressure is enough to support a column of water about thirty feet high.
Even if you could suck all the air out of a forty-foot straw, the water wouldn’t rise more than thirty feet. In space, where there isn’t any atmospheric pressure, a straw wouldn’t work at all.